Sonata Forms

Chapter 9: Sonata Form

Instrumental music written in the sonata-allegro form, also known as first-movement form, is commonly referred to as a sonata.  This helps distinguish it from a vocal form (cantata) or a keyboard piece (toccata).  This form evolved over recent centuries, and is still in use as a viable receptacle for a composer’s ideas. 

In general, most sonatas can be divided into three broad sections; the exposition, the development, and the recapitulation.  The number of themes, transitions, introductions and codas, methods of development, and tonal areas are subject to each composer’s creative approach.  Refer to the Sonata Form Line Graph in the Materials below, which shows all the elements that might appear in a sonata.  In later orchestral concertos, the sonata form usually has a double exposition, one for the ensemble and one for the soloist.  It also typically provides space for an improvisatory cadenza by the soloist near the end.  The Sonata-Rondo form is basically a 7-part third rondo (ABACABA) in which a development section replaces a theme in the second episode, part C.  In the classical period many of these forms closely resemble a seven-part Rondo, and might be more accurately referred to as a Rondo-Sonata.  A case in point is the fourth movement of Mozart’s Eine kleine Nachtmusik.